Reaction product of vinyltrichlorosilane, diethylene glycol, water and ammonia or anamine and method of making same



United States Patent nice Marvin C. Brooks, Middlebury, Conn., assignor to United States Rubber Company, New York, N.Y., a corpora- 1 tion of New Jersey No Drawing. Application October 5, 1955 Serial No. 538,771

5 Claims. (Cl. 260-454) This invention relates to the manufacture of composite structures of glass and resin, in which the bonding of the resin to the glass is particularly strong. More specifically, the invention relates to the preparation and use of a substance for improving the bond between the resin and the glass, which substance is obtained by modifying or activating, with small quantities of water and ammonia or an amine, a reaction product of vinyltrichlorosilane with diethylene glycol.

It has previously been found (see my US. Patent 2,754,- 237, issued July 10, 1956, and my copending application Serial No. 392,480, filed November 16, 1953) that when glass is pretreated by depositing on it a very thin surface coating of certain vinylsilane chemicals (including the above mentioned vinyltrichlorosilane-diethylene glycol reaction product in the unactivated condition) the composite glass-resin structure made from such a treated glass has greater strength, and is more resistant to loss of strength when exposed to moisture, than a similar structure made with clean untreated glass. It has also been found (see my abandoned application Serial No. 343,505, filed March 19, 195 3, which is a continuation-in-part of my abandoned application Serial No. 306,723, filed August 27, 1952) that a similar improvement may be obtained by using clean untreated glass and an uncured resin mixture containing a properly selected vinylsilane chemical in making the glass-resin structure. This second method has obvious advantages of simplicity, flexibility, and economy over the first method.

The above-mentioned unactivated vinyltrichlorosilanediethylene glycol reaction product is eitective in increasing the strength of a glass-resin structure made by this sec- 0nd method, as shown, e.g., by Example II of my abovementioned application Serial No. 343,505. However, the extent of the improvement obtained is found to be somewhat variable, and in particular to be less for resin mixtures which cure at a relatively low temperature and a relatively rapid rate than for mixtures which cure less rapidly. It has now been found that, if the vinyltrichlorosilane-diethylene glycolreaction product is activated in a certain novel manner before incorporating it in the resin in carrying out the second method, more consistent improvement is obtained under widely varying curing conditions. According to the inventiongthe novel activation involves causing the reaction product to react with small quantities of water and ammonia or an amine, as will be described in detail below. The practice of this invention will be, made clear by means of a description of the following items:

(1) Preparation of the vinyltrichlorosilane-diethylene glycol reaction product.

(2) Activation of this reaction product by reacting it with water and ammonia or amine.

(3) Incorporation of the activated reaction product into a liquid curable resinous mixture containing an ethylenic monomeric compound and a free-radical generating catalyst.

7 2,885,888 Patented May 5, 1959 These items are described in detail in the following:

(1) Preparation of reaction product.225 grams (2.12 moles) of diethylene glycol are placed in a vessel and 150 grams (0.93 mole) of vinyltrichlorosilane are added at room temperature with stirring. During addition of the silane, hydrogen chloride is evolved. The reaction mixture is then heated to 200 C. and held at this temperature for 2-3 hours, to complete the reaction and drive off the hydrogen chloride. The final product contains essentially no hydrolyzable chlorine.

This example uses 4.25 equivalents of diethylene glycol (1 equivalent being the weight which contains one gram molecular weight of hydroxyl), and 2.8 equivalents of vinyltrichlorosilane (1 equivalent being the Weight which contains 1 gram atomic weight of chlorine), or about 1.5 equivalents of glycol to 1.0 equivalent of silane. These proportions may be varied to some extent, but should be Within the limits 1.3 to 1.8 equivalents of glycol per equivalent of silane, and preferably within the limits 1.5 to 1.8 equivalents of glycol per equivalent of silane. Smaller proportions of glycol may result in insoluble gelled products, while larger proportions unnecessarily dilute the product. For further details on the preparation of the vinyltrichlorosilane-diethylene glycol reaction product, reference may be had to US. Patent 2,715,135, issued August 9, 1955, to M. C. Brooks and R. H. Ewart, the disclosure of which is hereby incorporated herein by reference.

(2) Activation of reaction product.The water and the ammonia or the amine (either concurrently or successively in any desired order) are slowly added to the reaction product with constant stirring, so as to insure rapid and complete mixing. Stirring is continued until an exothermic reaction occurs; this causes a temperature rise of about 10-20 C., and is usually complete in about five minutes. The activated product is ready for use as soon as, but not before, the exothermic reaction is completed. The activated product will keep indefinitely in a closed container; exposure to moist air causes a film of gelled material to form at the surface.

If mixing is not rapid enough, or if amounts of water greater than about 4% are added, gelation will occur. The preferred amount of water to be used is 2-3 based on the reaction product, and in any case I almost invariably use at least 0.5% of water. Water alone reacts very slowly, if at all, with the reaction product at room temperature; the ammonia or the amine serves to speed up the reaction, and may also itself enter into the reaction. The preferred amine for some applications is dimethylamine, since it, unlike the other amines tested, does not have a discoloring effect on the final'cured polyester resin. However, other amines workinsofar as their activating effect is concernedas well as, and in some cases perhaps even better than dimethylamine. Among the materials tested and found eifective are ammonia, monoethanolamine, diethanolamine, triethanolamine, dimethylamine, ethylamine, amylamine, triethylenetetramine. The preferred amount of material varies somewhat with the material chosen. The amount is kept to a minimum, to avoid discoloration of the resin and the activating effect on the cure of the resin. Amounts of ammonia or amine from 0.1% to 5% on the resin have been used, and in general I almost invariably use at least 0.05% of the ammonia or amine, but not usually in excess of 10% of the same.

The activated reaction product closely resembles the unactivated product in physical properties, being a liquid of light brown color, with a viscosity in the range to 1000 centipoises. The viscosity depends mainly on the equivalent ratio of glycol to silane, being very high for ratios below 1.3 to 1, and decreasing rapidly as the ratio is increased above 1.3 to 1.

Using the method of this invention, attempts have been made to activate other reaction products of vinyltrichlorosilane with monoand dihydric alcohols, including the following:

they appear to undergo a similar reaction when treated with water and amine.

' (3) Mixing activated. reaction product with resinfofhiingfliqujd The activated reaction product is preferably mixed with the liquid mixture of the resin-forming constituents just before the cure is started; it is con-v venient to add the activated product at the same time as the 'cure catalyst is added. Prolonged standing after adding the activated product must be avoided, since the beneficial effects of the addition are lost. Standing periods up to one day may be tolerated in some cases with out serious loss of beneficial efiect; however, it is preferable to bring the mixture into contact with the glass as promptly as possible after adding the activated reaction product, and to cure the mixture at once.

(4) Molding and curing.The liquid resin-forming.

mixture containing the catalyst and the activated reaction product of this invention is brought into contact with the glass portion of the desired composite structure, and kept there during the curing process, using if necessary a suitably designed mold, as is well-known in the art.

The following explanation of the improved results obtained with the activated reaction product is offered, without however intending to limit the claims for invention by any such explanation. It is believed that the reaction product or additive acts by migrating to the glass surface and becoming attached to it, either by adsorptive forces or more probably by chemical reaction between the additive and surface constituents of the glass, before the cure starts. The vinyl group of the additive subsequently, duringcure of the resin, copolymerilzes. with theresin-forming constituents, and is incorporated into. the resin, structure, thus. providing a chemical bond between resin and. glass. If the vinyl gro p copolyrnerizeswith the resin-forming constituents before. theadditiyereaches and becomes.- attached to the gla lsurfacc, no bond between resin and glass is obtained. The improved results obtained with the activated reaction product as compared with those obtained with the unactivated reaction product are believed to be due to a faster rate of one or both of the steps involved in adhering the additive to theglass, i.e. migration of the additive tothe. glass surface, and reaction of the additive with the glasssurface.

Resins. The curable resinous compositions with which the activated vinyltrichlorosilane-diethylene glycol reactionproduct is admixed in accordance with theinvention are'well-lcnown materials and comprise a polymerization catalyst, typically an organic peroxide, an esterification productof an alpha-ethylenic alpha, beta-diearboxylic acid with a glycol, this esterification product beinig an advanced linear polyester containing unesterified carboxyl groups and having an acid number of from 5 to and being dissolved in and copolymerizable with a liquid monomeric unsaturated polymerizable compound containing an ethylenic linkage and being immiscible with water. Polyesters of this type are described in US. Patent 2,195,362. In use, unsaturated linear polyesters of this type are mixed with a polymerizable monomer, for instance, styrene, diallyl phthalate or triallyl cyanurate, and the mixture is; cured to solid form by heating in the presence of a suitable catalyst. Typical unsaturated linear polyestercopolymerizable monomer resin mixes used in practicing the invention are described in US. Patent 2,255,313 and in British Patents 540,168 and 540,169. As descriptive of such mixes, the disclosure of said, patents is hereby incorporated by reference in order to avoid undue repetition. As is well-known, the unsaturated dicarboxylic acid may be partially replaced by another dibasic acid which may be typified by adipic acid, succinic acid, sebacicacid, phthalic acid, tetrachlorophthalic anhydride, and which 1 may be used in amounts up to'3 moles per moleof unsaturated dicarboxylic acid.

Reference may be had' to my previously mentioned abandoned application Serial No. 343,505 for further details concerning the incorporation of the vinyltrichlorosilanediethylene glycol additive inthe resin composition, as well as for further details concerning the formulation and curing of the resin composition, since the details there disclosed concerning suitable materials, proportions, curing conditions, etc., apply to the present invention also, the only difference being that in the present case the additive is modifiedwith water and an amine as herein described. Thus, as disclosed in said abandoned application, the amount of the vinyltrichlorosilane reaction product added to the resin will generally range from 0.1 to 10% of the weights of the esterification product and monomer.

Glass.The glass used in the composite structure to which the invention is applicable may be in any desired form. The invention is especially useful in making structures containing glass fibers, whether the fibers be present as individual fibers, or as components of a yarn, cord, or fabric. In any case, the surface of the glass should be clean, i.e. it should be free from any extraneous material which would adversely atfect the bonding of the resin thereto. In particular, it should be free from organic material which would adversely afiect the degree of bonding, especially those organic materials which are applied to glass fiber during manufacture for various purposes such as for libricating the fibers or sizing them. The maximum efiectiveness of the reaction products is obtained when well cleaned glass fibers are used. If a sizing hasbeen applied'to glass fibers it may be removed by heatingthem to'tempera tures within the range of 600 =to' 900= F; forsay-12 to 7-2 hours before bringing them intocontact with the resin-reaction product mixture.

Testing. met-h0ds,-In demonstratingthe eflfectof the invention on glass fiber-reinforced'- polyester compositions, we have chosen to report the flexural strength of molded fiat sheets of the compositions. It is well-known to those experienced in the field that changes in tensile strength and compressive strength generally parallel changes in flexural strength.

The most significant improvement; in the reinforced :polyester compositions brought about by the method'of the invention is greater strength retention after aging in water. As is common practice among those experienced in thetield, we havemeasured this property by determining the flexural strength of the. compositions after they h ve n mm rsedin. 0i1, .ng.:water for- 3 hours. This aging treatment is gene r a lly,--recognized. tobc at least equivalent to standing onemonth, in; waterat room temperature.

The samplesused for; testing Were-laminates constructed with 12 plies of glass fabric which had beengpleaned by heating for 48 hours :at'750" Fa The glass fabric'was thoroughly saturated with resin, care being taken to remove all air bubbles. The laminates were then cured in molds at atmospheric pressure, or in a laboratory press at approximately p.s.i. pressure. The curing cycle varied. Thickness of the cured laminates was about Vs inch, and the glass content was about 65% by weight.

Examples-In the following additional examples illustrative of the invention, two resin-forming mixtures were used, as described below.

Resin mixture A.-98 parts of maleic anhydride, 148 parts of phthalic anhydride, and 163 parts of propylene glycol are heated for 3 hours at 200 C., the final halfhour being at reduced pressure. The resultant alkyd resin has an acid number of 55. Resin mixture A consists of 67 parts of this alkyd and 33 parts of styrene.

Resin mixture B.-88 partsof maleic anhydride, 148 parts of phthalic anhydride, 29 parts of tetrachloro phthalic anhydride, and 130 parts of ethylene glycol are heated about 4 hours at 220 C. The alkyd so prepared has an acid number of 40. Resin mixture B is a combination of 70 parts of this alkyd and 30 parts of styrene.

Example 1.Three series of laminates were made, using as activator various amounts of three different amines and of water, other factors being the same for all experiments, namely:

(or activated reaction product) Results are shown in the table below:

Green Flexural Activator (as percent of reaction product) Flexural Strength Strength After 3 hr.

(p.s.i.) Boil (p.s.i.)

None 66, 800 46, 700 0.5% ethanolamine 0.5% water. 70, 800 50, 000 1% ethanolamine 1% water- .200 56, 300 2% ethanolamine 2% watch--- 71,000 60, 100 one 66, 000 44, 500 0.28% ammonia 0.72% water- 68, 100 49, 600 0.56% ammonia 1.44% water- ,800 900 1.12% ammonia 2.88% water- 73, 900 58, 500 None 66, 000 44, 500 0.4% Dimethylamine 0.6% water. 70,200 51, 800 0.8% Dimethylamine 1.2% water... 66, 800 52, 500 1.6% Dimethylamine 2.4% Water 70, 800 56, 300

Comparing thesamples containing activated reaction product with those containing unactivated reaction product, it will be observed that the activator had a definite beneficial elfect in improving even the green fiexura-l strength, and a marked beneficial effect in improving the fiexural strength after exposure to moisture.

Example 2.In this example, the amount of water in the activator was varied with constant amine content, other factors being as in Example 1.

Green Flexural Activator (as percent of reaction product) Flexural Strength Strength After 3 hr.

(p.s.i.) Boil (p.s.i.)

2% Ethanolamine (no water) 62,000 45, 300 2% Ethanclamine 2 H 63, 000 53, 800 0 2% Dlmethylamine 0 8% H 64, 900 50, 200 0.2% imethylamine 1.3% HgO 66, 500 53, 400 0.2% D ethylamine 2 3% H20. 68, 400 54, 900 0.4% Dlmethylamine l 1% H20. 66, 000 52,300 0.4% Dimethylamine 2 2% H2O- S00 800 0.4% Dimethylamine 3.2 H; 65, 600 56, 700 0.8% Dimethylamine 1.7% H2O 63, 900 100 0.8% Dimethylamine 2.2% HzO 63, 400 53, 700 0.8% Dimethylamine 3.2% H20 67, 800 57, 200

The importance of water as an activator is clearly shown by the enhancement of fiexural strength as the water is increased, particularly in the boiled samples.

Example 3.In the experiments of this example, three difierent catalysts and three corresponding curing conditions were used as follows:

Cure I.2% methyl ethyl ketone peroxide+0.15% cobalt naphthenate on the resin. Cured 24 hours at room temperature, followed by 1 hour at 212 F.

Cure II.1.5% benzoyl peroxide on the resin. Cured 20 minutes at 175 F.+15 min. rise to 275 F.+10 min. at 275 F.

Cure III.1% ditertiarybutyl diperphthalate on the resin. Cured 20 min. at 200 F.+15 min. rise to 300 F.+10 min. at 300F.

Using each cure, samples containing 1% of plain (unactivated) reaction product and samples containing 1% of reaction product activated with .4% dimethylamine and 2.6% water were made. Resin A was used in all samples.

Green Flexnral Reaction Product Used Cure Flexural Strength Strength after 3 Hr.

(p.s.i.) Boil (p.s.i.)

I 66, 800 47, 200 I 65, 600 56, 700 II 63. 600 46, 800 II 60,900 52. 200 III 72,100 58, 900 III 07, 500 63, 000

The superiority of the activated over the unactivated reaction product is clearly shown by comparing the flexural strength of the boiled samples, particularly those made with the more active curing agents.

Example 4.This example shows the applicability of the invention to two different resins, using two different curing conditions (cure I and cure II of Example 3), and using 1% of the activated addition product of Example 3.

Green Flexural Resin Cure Flexural Strength Strength after 3 hr.

(p.s.i.) Boil (p.s.i.)

Resin A I 65, 500 53, 000 Resin B--. I 67, 400 57, 600 Resin A II 60,900 52, 200 Resin B II 68, 700 58, 000

Example 5.-This example shows the relative ineifectiveness of the activation method of the invention when applied to vinylsilanes other than the vinyltrichlorosilanediethylene glycol reaction product of the present invention. The vinylsilanes were prepared in a manner similar to that described above for the reaction product of the present invention, using vinyltrichlorosilane and various alcohols and diols. The table below shows the alcohol or diol used in making the reaction product and the amount of reaction product on the resin; the kind and amount of activator used; and the results of strength tests on samples cured as in cure I of Example 3. Resin A was used.

Green Flex. Activator Flexural Strength Strength Att. 3 hr.

(p.s.i.) Boll (p.s.i.)

1% of z-chloroethanol react. prod.

none- 69, 200 52, 0.8% d1methylamine+1.2% H20" 64, 700 46, 500 1.6% dimethylamine+2.4% H1O--- 64, 800 43. 700

1% of propylene glycol react. prod.

none 59, 000 38, 000 2% ethanolam1ne+ H10. 63, 000 38, 400

1%of2;4-pentanedlolireact. prod.

Example 6.-This example illustrates'the loss of eflectiveness encountered when the resin mixture containing the activated. reaction product is stored before use. A batch of resin mixture A containing neither catalyst nor activated reaction product was divided into three parts. To one of these parts (test resin 1) there was added at the start of the experiment 1% of activated reaction product; to a-second part (test resin 2) 2% of activated reaction product was added at the start; to the third part control resin) no reaction product was. added at the start. After storage for various periods at room temperature, catalyst was added to portions of test resins 1, and 2, and catalyst and 1% of activated reaction product were added to the control resin; the portions were. then cured. usingcure I of Example 3, and the resulting samples. tested. Results are shown in the table below.

It will be seen that, while the green samples show no significant differences. betweenthe difierent treatments, the reaction product isinetfective in maintaining strength inthe boiled product when itadded- 5- days; er -more before I cure. I

Having thus described myinvention', what I claim and desireto protect by Letters Patent is:

1. A composition useful forimproving bonding of resin to glass comprising a reaction produet'of- 1 equivalent of vinyltrichlorosilane with from 1.3 to 1.8 equivalents of'diethylene glycol modified with from 0.5 to- 4% of water and from 0.05 to 10% of amaterial selected from the group consisting ofammonia and aliphatic amines.

2. A composition as inclaim 1 in which the amine is dimethylamine.

3; A method of modifying; a reaction product of 1 equivalent of vinyltrichlorosilane with from 1.3 to 1.8 equivalents of diethylene glycol, which comprisesreacting said reaction product with from 0.5 to 4% of water and from 0.05 to 10%; of a material selected from the group consisting of ammonia and aliphatic-amines.

4. A method comprising mixing the reaction product ofl equivalent of vinyltrichlorosilane with'from 11.3to 1.8 equivalents of diethylene glycol modified with from 0.5 to 4% of water and from 0.05 to 10% of a material selected from the group consisting of ammonia and aliphatic amines with a curable-polyester resin composition comprising an organic peroxide polymerization catalyst, and esterification product of an alpha-ethylenic alpha, beta-dicarboxylic acid with a glycol, said esterification product being a linear polyester containing unesterified carboxyl groups and having an acid number of from 5 to 100, and a, liquid miscible with and copolymerizable with said esterification product to yield a solid} resinous material, which liquid is a monomeric unsaturatedpolymerizable compound containing an ethylenic linkage, the amount of said reaction product being equal to from 0.1 to 10% of the weights of said esterification product and monomer, and therafter curing said polyester resin composition in contact with a clean glass surface, whereby a strong adhesive bond is formed between the glass and the resin.

5. The product of the method of'claim 4.

References Cited in the file of this patent UNITED STATES PATENTS 2,715,135 Brooks et a1. Aug.,9v,- 1955 2,798,020 Balz et al July2; 1957 FOREIGN PATENTS 575,752 Great Britain Mar; 4, 1956 OTHER REFERENCES.

Bjorksten et al.: Modern Plastics, volume, 29, No. 11', July 1952 ,pages 124 and 188. 

1. A COMPOSITION USEFUL FOR IMPROVING BONDING OF RESIN TO GLASS COMPRISING A REACTION PRODUCT OF 1 EQUAVALENT OF VINYLTRICHLOROSILANE WITH FROM 1.3 TO 1.8 EQUAVALENTS OF DIETHYLENE GLYCOL MODIFIED WITH FROM 0.5 TO 4% OF WATER AND FROM 0.05 TO 10% OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF AMMONIA AND ALIPHATIC AMINES. 